I purchased the factory blower (UZY5) which comes equipped with a molded plug and SJT cord, here is the documentation for the fan (minus instructions on plugging it into a receptacle that is pre-wired into the fireplace - very helpful):

The fireplace has a handy box within the bottom of the unit with the one and only electrical KO into the fireplace from the outside of the unit into this box. I was hoping to use a P&S DDH16P fan control to vary the motor speed (since Lennox has been unable to provide their blower control for 6 months and counting):http://www.passandseymour.com/pdf/N14_N38.pdf

My original thought was to have the DDH16P control a receptacle mounted in the fireplace junction box, which is designed to accept a receptacle for plugging in the molded plug-equipped blower. However, I believe it is not to code to control a receptacle with a dimmer (and I assume a fan control as well). So, I figure that I could have the receptacle receive direct power and insert the fan speed control in the loop where the factory dimmer is supposed to go (see sketch above)...except there is only the one KO into the bottom of the fireplace and that goes into the handy box (where the receptacle will be). And yes, the factory blower control unit (VRUW) is also a wall mounted unit - so its control wires are supposed to get inside somehow other than through the louvers in the front of the unit.

Possible options seem to be:

1) Can the fan speed controller control the receptacle (maybe there is an exemption for a receptacle installed within an appliance)?

2) Can the blower be hard wired into the junction box and control with the fan control (this means cutting off the plug and using a strain-relief bushing into the cover of the handy box)? Not sure I can install a cord in this way, either...

3) Can a second wire be routed into the fireplace, either by putting two NM 14-2 through a single bushing and out the side of the handy box that will have a receptacle installed in it (don't think so), or by drilling another hole in the fireplace? (for the record, their tech support indicated they thought there were additional knockouts in the fireplace - there aren't anymore than the one)

This is a permitted job and I will be talking to the electrical inspector prior to starting the electrical (I just want to know what I am talking about/proposing).

What do you mean be happy with what I have? - I don't have anything. I have no documented installation procedure from this manufacturer for installing their (or any other) blower control.

Forget what I want to use (alternate controller).

They provide one single KO into a handy box within the fireplace (where they mention placing a receptacle), a fan with a molded plug, and a wall-mounted speed control that is supposed to be spliced into the fan at the junction shown at the diagram above (everything in the diagram above is contained within the bottom of the fireplace).

There are no instructions from the mfg on how to install the blower control (no wiring diagram beyond the picture shown above for the fan). I have called their tech support multiple times about this issue with no results.

How would you wire this to code (there is an existing light switch in the chase that can be made into a double gang)?

Edit: I plan to have my master electrician do this work, but I have learned in the past as the HO to always make sure you know how things are supposed to work. As I mentioned, I also want to discuss the plan with the EI up front to avoid pain later.

I called tech support again. They still do not have documentation, but told me what to do. They said they may be able to write up a procedure, if required by my EI.

They said run the 2 NM wires through the single KO with a bushing into the handy box (one from the fan control switch and one from the supply line). Hook up a receptacle to the supply line - plug the fan into that. Run the second wire through the KO in the side of handy box (will confirm its existence later when I get home) with a bushing and wire into the connectors shown in the original diagram.

Seems so simple now, but I still wonder why they would not have a better wiring diagram/instructions included with any of the three components they are selling...

I have no documented installation procedure from this manufacturer for installing their (or any other) blower control.Pete

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Downloaded this from the link you posted in your first post

Installation of the blower kit
model UZY5
Note: This blower kit can easily be installed when
the fireplace has a pre-installed junction box.
You just have to plug them in.
Rating: 120 Volts, 60Hz, .63A.
The blowers have magnetic blower mounts.
The junction box (factory installed on approved
fireplaces for the use of this blower kit) must be
connected to 110 VAC service before permanently
enclosing the fireplace. The access hole
for connecting the 110 VAC is located on the
lower right exterior side of the fireplace.

Installation instructions:
1. Open the bottom louver of the fireplace.
2. Place each blower kit into the fireplace
side opening 1" from the back of the
fireplace.
3. Install the automatic blower activator on
the side of the firebox (the blower activator
has a magnetic mount).
4. Plug the blower kit into the junction box.
5. Ground both blowers to the back panel
using the green screws (see Figure 9).

Based on a quick read, it seems to be that IF it was set up to accept the fan, there would already be an recepticle in the box. It also appears from their diagram that there is a plug connector that allows you to insert the variable speed control (reostat) in the fan assembly cord. It may be that this unit was not set up to accept the fan and adding it would void the warranty. Any wiring done would need to have the proper temperature ratings, or the insulation could fail. Same is true with any plugs, connectors, or other additions.

There is no receptacle to be installed on the fan assembly. The receptacle is part of the house wiring and the fan assembly plugs into this receptacle.
The fan speed control that is required by to be used with this fan assembly will be wired in the box that has a hole it.

Look at the diagram

Where it says â€œconnector for optional rheostatâ€ is that junction box with the hole in it for the conductors from the fan speed control (rheostat)

Spoke to the EI. I described how the mfg said to run 2 wires and put the rheostat in-line after the plug and showed him the instruction sheet for the blower.

He indicated that my electrician should just wire the fan control to control the receptacle. I said that I thought is was against code to control a receptacle with a dimmer or fan control, for example in a wall. He described it as not smart but not against code. If he is OK with it, I guess that is the way to go.

Of course, we will make sure not to plug the vacuum or anything else into the receptacle inside the fireplace.

Spoke to the EI. I described how the mfg said to run 2 wires and put the rheostat in-line after the plug and showed him the instruction sheet for the blower.

He indicated that my electrician should just wire the fan control to control the receptacle. I said that I thought is was against code to control a receptacle with a dimmer or fan control, for example in a wall. He described it as not smart but not against code. If he is OK with it, I guess that is the way to go.

Of course, we will make sure not to plug the vacuum or anything else into the receptacle inside the fireplace.

Pete

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It doesnâ€™t matter about what the EI had to say about it the problem is much deeper.

The fan control MUST be the one recommended by the manufacturer and not a dimmer on a receptacle.

The type of method for controlling the speed of the fan motors is different than the method for dimming a receptacle. What you propose could be catastrophic for the motors.

I strongly recommend that you comply with the recommendations of the manufacture and use the speed control that they will have to stand behind instead of doing something that may end up costing you in the long run.

As to the statement of your EI this is what the National Electrical Code 2008 Edition has to say:

404.14(E) Dimmer Switches. General-use dimmer switches shall be used only to control permanently installed incandescent luminaires unless listed for the control of other loads and installed accordingly.

The verbiage (â€œunless listed for the control of other loads and installed accordinglyâ€) means that the dimmer you are wanting to install would have to be listed as a control for the fan motors or it can not be used.
Should the dimmer that you propose to use not be of the rheostat type then the motors would not be controlled. This is evidenced in the language that the manufacturer makes with, â€œConnector for optional rheostatâ€ implying that the controller needed for the motors is a rheostat not an electronic dimmer. This verbiage now call into play 110.3 (B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

Should you decide to go with the advice of your EI then get this permission to stray from the NEC in writing as outlined here

90.2 (C) Special Permission. The authority having jurisdiction for enforcing this Code may grant exception for the installation of conductors and equipment that are not under the exclusive control of the electric utilities and are used to connect the electric utility supply system to the service-entrance conductors of the premises served, provided such installations are outside a building or terminate immediately inside a building wall.

Special Permission. The written consent of the authority having jurisdiction.

If you have it in writing it might come in handy should something go wrong that would call for an insurance claim. With out the permission in writing it might be a troublesome situation with a insurance claim and a noncompliant code installation.

The AHJ said to wire the fan control (not dimmer) to control the receptacle. I was quoting the regulations regarding a dimmer not controlling a receptacle to the AHJ and indicating I thought this may apply to fan controls as well. He said it was fine, and 404.14(E) does not preclude (as you have quoted).

Can a fan control control a receptacle by code?

If yes, this is the source of my overall confusion and it is probably time to purchase the electrical code, so I can read it myself instead of catching bits on-line and getting confused.

I am confident the fan will not be damaged by the control itself. Also, the mfg has not been able to deliver their speed control in 6 months. I realize the mfg may not stand behind the fans if I use another speed control, but at that point, I will just buy new fans from Grainger, anyway.

The DDH16 fan speed control is an electronic device and the fan diagram calls for a rheostat. There is a big difference between the two and the electronic device and motors could suffer severe damage if used together.

Even if you didnâ€™t look at 404.14(E) there is no way around 110.3(B) which calls for all equipment to be installed according to the listing and labeling of the equipment. The manufacturer of the fans calls for a certain type of speed control to be installed and anything else would be outside the listing of the fans.

My concern is not the illegal use of a dimmer on a receptacle but instead the emit danger of the electronic device controlling a motor designed for a rheostat.

If I were going to control the receptacle I would use either a single pole switch or a line voltage thermostat and let the fans run at full speed but I would not use any other fan speed control except the one the manufacturer suggest to be used.

EDITED TO ADD:

Looking at the listing of the dimmer that you posted a link to it is easy to see that the device is an electronic device that contains a capacitor. The fan motors that you provided a link to calls for a rheostat which is a variable resistor. There is a big difference between the two and one will not replace the other.

Judging by your post you seem to be bent on installing this device to a receptacle for controlling the speed of the fan motors so I shall leave you with one more piece of advice.

If you do install this device to control the speed of the fan motors please also install a small powder type fire extinguisher close to the dimmer for when the smoke starts coming out as there might be come sparks coming out with the smoke. The fire extinguisher can be used to keep the sparks from starting a fire that is if someone is home when it happens.

I am bent on installing something for controlling the fan, but definitely not something improper, which is why I was asking questions in the first place.

I have called Pass and Seymour and you are correct about all of their controls being electronic (cutting the sine wave).

Lennox has not been been able to deliver their speed control for 6 months!! So, I am hoping to find another rheostat to do this and I thought (incorrectly as you thankfully point out) the above might be an option.

I truly appreciate your insight and knowledge. If only the manufacturer was as helpful.

Just so you know, I still have the Lennox device on backorder, but I am frustrated with the situation.

BTW, running the fan on full speed at all times is not reasonable - they are too loud in close proximity, which is why Lennox designed the system and made a rheostat controller.

If I can find a true wall mounted rheostat, is that OK to install?

As i read it, the Lennox fan manual does not say I need to install their rheostat. The manufacturer does not specific part number VRUW must be installed to control the unit in their documentation...just says a rheostat. The stove manual lists VRUW as a part available, but does not specify that only it must be used as the blower control.

I am going to try other vendors for the VRUW, as well.

If you have other recommendations on a true wall mounted rheostat, I am all ears, but I realize you are indicating that you would only use the VRUW.

Fireplace Blower
The fireplace comes equipped with a heat activated blower. It is located
in the bottom of the fireplace, towards the back. It uses 120 V and must
be connected to the main electrical circuit by a qualified electrician. For
connection, use the electrical box supplied with the unit located on the
bottom right corner of the fireplace.

If you wish to adjust the blower speed, the variable speed control (VRUW)
provided must be installed in line with the wiring. Again, use a qualified
electrician for installation.
-
-
-
Only the blower available with the fireplace can be used with the gravity
kit. For safe installation, the gravity kit must meet the following requirements:

I found this by searching the site you posted for the fan kit mentioned.

In the second paragraph is these words, â€œIf you wish to adjust the blower speed, the variable speed control (VRUW) provided must be installed in line with the wiring.â€

This is the instructions that the manufacturer included with their installation instructions and the NEC makes this statement in Section 110.3(B) â€œInstallation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.â€

The word â€œshallâ€ found in Section 110.3(B) Installation and Use, must be followed. The installation instructions clearly state that unit VRUW is to be used. In order to be code compliant no other speed control nor from the last sentence that I posted no other blower kit or motor can be used for this fireplace.

Look at the whole picture instead of just the fans. You are installing something that will produce a lot of heat (fire hazard) and then installing a blower on this equipment. I wouldnâ€™t want to do anything that would cause those blowers to add to this danger (fire hazard).

This fireplace was tested using their components such as the blowers and speed control outlined in their installation instructions. To use anything different would be stepping out side the realms of the testing and should not be considered for use.

Well then quit posting and start installing if you don't think that anything applies

Why even waste time asking if you already have the answer?

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EDIT: I worded that badly - of course the code applies - just not sure the install would be in violation of that part of the code. Besides, you convinced me that installing the VRUW is in my best interest.

I appreciate your help and I am going to focus my energies now on getting the manufacturer to supply the VRUW. My electrician is on vacation in the near term anyway.

Most of these rheostats are mounted in metal boxes with side straps. The box mounts inside under the fire box where all the other electronics and gas valve are. Since it mounts to the metal enclosure it is inherently grounded and needs no additional green wire.